Dorothy asked me some time ago what I thought was the first book in the library. A strange question. I found it very difficult to answer. I wasn't sure why. Then I realised that it was because my image of the library was very continuous. It was a shape without a beginning or an end. This is a universe without a boundary. You can't hit up against a deadend. I can keep on journeying through one door into the hexagon and out the opposite door. Or climb up and down between the layers of the library. But the library isn't infinite, just without a boundary. So if I keep on journeying I will eventually come back to where I started.
But as I thought a bit more about the first book and the beginning, I realised that the story of the Library Babel mirrors the two first steps we make in navigating the world around us: to count and to explore the space around us. I believe that animals are almost programmed by evolution to be mathematicians. Counting is essential for survival. To assess whether there are more of you than there are of the enemy will inform the decision to fight or fly. To assess the the nature of the space around us allows us to judge whether we are out of range of our prey or our predator. Those that can count survive. As Plato wrote across the top of the Academy: Let no one ignorant of geometry enter here.
So maybe the first book contains the numbers 1, 2, 3,... and pictures of triangles (although the books have no pictures...or do they?)
Galileo's famous quote: The universe cannot be read until we have learnt the language and become familiar with the characters in which it is written. It is written in mathematical language, and the letters are triangles, circles and other geometrical figures, without which means it is humanly impossible to comprehend a single word.